This invention related to a method of attaching a flexible cover to a rectangle storage space, such as a pickup truck bed or boat cockpit. This attaching method seals the flexible cover to the sides of the space to provide weatherproof storage, retain the contents within that space, and reduce the aerodynamic drag of that space, when the vehicle is travelling. By supporting the cover continuously, with a metal frame, it has greater strength to withstand the forces, of the vehicle movement, than other attaching methods. This invention fills the need for an attaching method, which does not require any holes drilled in the top or outside of the truck bed.